It is known to incorporate various phosphites with polymers as disclosed in U.S. Pat. No. 3,305,520 and phosphites with tetraaryl tin as shown in Canadian Patent No. 727,700. However, these references deal solely with phosphites such as triaryl and trialkyl phosphites. Due to increased molding temperatures and use temperatures of molded shapes of polycarbonates, it is increasingly more important to prepare polycarbonates having increased stability to thermal degradation or discoloration due to elevated temperatures. Phosphonites have been known to provide stabilization for polycarbonates as disclosed in copending applications Ser. No. 28,054, filed Apr. 13, 1970, now abandoned.
Therefore, it is an object of the instant invention to provide a thermally stable polycarbonate.
Another object of this invention is to provide a thermally stable polycarbonate stabilized with minor amounts of a phosphinite present.
Yet another object of this invention is to provide a thermally stable polycarbonate composition having in admixture, a polycarbonate, minor amounts of a phosphinite and an epoxy.
These and other objects of this invention will become apparent from the following detailed description thereof.